[Feature request] add markings so the annotation can be mixed with other comments

[estani]

The comment block get replaced completely, which prevents other annotations/documentation for being used in the same position.

Proposed solution:

Add a marking to the beginning and end of the annotated comment block, so only that block get removed (and add option to behave like now, so annotations can be migrated)

A block might look like this:

# == Schema Information
#
# Table name: user
# 
#  id              :integer          not null, primary key
# ...
# == End of Schema Information

Everything between # == Schema Information and (optionally?) # == End of Schema Information can be wiped out and recreated, the rest is to be left intact.

[ixti]

There are --wrapper-open and --wrapper-close params, which, I believe, should be respected in this case (they are not ATM).